﻿<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
    <style>
        body {
        height:1000px;/*让窗体出现滚动条*/
        }
        .fixed {
            position: fixed;
            left: 100px;
            right: 100px;
            top: 100px;
            bottom: 100px;
            width: auto;
            height: auto;
            border: 1px solid blue;
            
        }
        .absolute {
            position: absolute;
            left: 100px;
            right: 100px;
            top: 100px;
            bottom: 100px;
            width: auto;
            height: auto;
            border: 1px solid red;
        }
		.relative{
			position:relative;
			left: 100px;
            right: 100px;
            top: 100px;
            bottom: 100px;
            width: auto;
            height: auto;
            border: 1px solid green;
		}
    </style>
</head>
<body>
    <div class="fixed">fixed定位</div>
    <div class="absolute">absolute定位</div>
	<div class="relative">定位</div>
</body>
</html>